Method of and apparatus for flanging cans



Dec. 16, 1947. J. COYLE 2,432,658

METHOD OF AND APPARATUS FOR FLANGING CANS Filed April 20, 1945 2 Sheets-Sheet l I I I J5 I I 20 "A "I'll,

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A} I I 26 26 2a 28 J3 s Via HA 1E WW I v 7 29 Joi C 5 I L r a I Dec. 16, 1947. J. COYLE METHOD OF AND APPARATUS FOR FLANGING CANS Filed April 20, 1945 2 Sheets-Sheet 2 E 1 E: E. E1 1325 XXX c/07Z7z 6034 6.

Patented Dec. 16, 1947 METHOD OF AND APPARATUS FOR FLANGING CANS John Coyle, Baltimore, Md., ass gnor to Continental Can Company, Inc., New York, NIX a corporation of New York Application April 20, 1945, Serial No. 589,368

15 Claims.

The invention relates generally to the art of manufacturing cans, and it primarily seeks to provide a novel method of and apparatus for forming the flanges which are provided at the ends of the can bodies and adapted for being rolled into the seam structures by which attachment of the container end closures is effected.

According to prevailing practices of flanging cans bodies, no practical method or means is available for definitely determining the length of the body hooks formed. by the downward bending of the can body end flanges during the seam securing of end closures thereon, or in other words no means or method for definitely determining the line about the can body end flange whereat the flange will turn downwardly in the formation of the body hook. Thus, there has been a lack of uniformity in the formation of cans and some have been of slightly different lengths than others.

In the usually practiced method of forming can bodies, theflanges are formedby bringing about relative endwise movement between each can body and a forming die to cause the latter to engage in the end of the body and turn a flange outwardly at the end thereof. During the process of bending said flange, the end of thebody flares outwardly until it strikes the end wall of the forming surface on the die andthen flares outward against said wall, the flare gradually widening until it strikes the circumferential abutment ring or flange of the die which limits outward turning of the body flange. Continued endwise movement of the body then collapses the flare against the die wall, the latter being curved to determine the curvature of the juncture between the body wall of the'containen' and the outwardly extended portion of the flange flattened against the end wall of the die. The metal of the body'flange is stiff and springy and it is practically impossihle to determine accurately "where the hook willbend in th e si bsequent' for mation of the closure attaching seam, or ih other words to definitely'dtermine the length'ofthe 'hody hook. Thisproblern is particularly troublesome at the cross-over area, that is at'the position of the side seam where the flange is turned in overlapped thicknesses of metal. This practice results in provision of flanges which are irregular in shapebecause of differences in the stiffness of the metal and the lack of means for positively causing the turning flange "to conform' to the shape ofthe die, by reason of the fact that h flan s a e unqrra d ou war l 9 the armsl t t e a was te d ng tra 2 set up incident to the outward flanging of the body edge portion often result in bursting of the solder bond and opening of the lap seam portions of the customarily formed lock and lap seams.

After the flange is formed on a can body, the length of the hook which will be formed in the process of attaching the closure depends upon the pressure applied between the chuck and the base plate at the time of seaming. If the pressure is excessive, it will cause the cover to break down the flange and produce a long body hook and a correspondingly short cover hook. If too little pressure is applied, the body hook will be short and the cover hook will be relatively long. As before stated, according to the prevailing practice,

there is nothing to determine where the bend in the flange will take place in the formation of the hook, except experience on the part of an operator as to the correct base plate pressure to apply by adjustment of the closing machine and the seaming rolls to give the desired length of hook. 'It often happens that unsatisfactory containers are produced because o f lthe formation of body hooks which are too short and whichresult in faulty sealing of the containers. In order to avoid this difliculty many operators have adopted the practice of providing body hooks which are longer than necessary so thatin obtaining the usual percentage of hooks which are shorter than the average length of hook being made, said shorter hooks will still be of satisfactory length.

Therefore it is an outstanding purpose of the present invention to provide a novel method of andmeans for forming can body flangesin a manner permitting definite determination of the line about which the flange will bend in forming the base of the body hook or the juncture of the hook with the body so that all containers'can be made with hooks of uniform length thereby assuring that the completed containers .wi-ll be of correct length.

An object of the invention i .to provide a novel method of fianging can bodies which comprises, gradually bringing about endwise contact between the can'body and an outwardly curved fla ging surface formed on a flanging die while simultaneously revolving a grain breaking roll externally against the metal itself to constitute the finished flange, breaking the grain of the metal as it passes between the grain breaking roll and the flanging surface and shaping it to the outwardly curved flanging surface to the predetermined limit of a circumferential retaining wall.

' Another object of the-invention is to Provide a novel flanging method of the character stated in which the grain breaking contact of the grain breaking roll with the can body flange being formed is terminated at a line about the turned flange at which the flange is subsequently to be turned to form the body hook, thereby to reduce the resistance to bending of the flange over the portions thereof contacted by the roll and definitely determine the length the hook will have when subsequently formed during the seam securing of a closure on the can body.

Another object of the invention is to provide a novel method of flanging can bodies which comprises the steps of forcing the can body endwise against a die having an outwardly curved flanging surface thereby gradually to force the die into the can body end, engaging a rain breaking edge in rolling contact externally against the body end edge portion being turned into the flange, said grain breaking contact being effected opposite the outwardly curved die surface while continuing to bring about relative endwise movement of the die and can body, thereby to cause the turned flange to conform to the outwardly curved flanging die surface, and terminating the grain breaking edge contact at a definite point opposite the die surface to predetermine the line about which the body hook will turn during subsequent seam securing of a closure on the can body.

Another object of the invention is to provide a novel apparatus for flanging can bodies, said apparatus comprising a flanging die having a portion insertible in the end of a can body to be flanged and including an outwardly curved flanging surface, means for supporting a can body, means for bringing about relative endwise movement between the die and the support to force the can body end edge portion endwise over the curved flanging surface,v a roller having a grain breaking edge, means for presenting the grain breaking roller edge against the external surface of the can body end edge portion as it is being forced endwise over the curved flanging surface, and means for bringing about relative rotation between the grain breaking edge and the die and can body being flanged thereagainst.

Another object of the invention is to provide an apparatus of the character stated in which the flanging die has an outwardly directed flange and the outwardly curved flanging surface terminates in an undercut under said flange disposed to provide an abutment shoulder for definitely determining the extent of outward turning of the can body flange.

Another object of the invention is to provide an apparatus of the character stated in which the outwardly directed die flange snugly engages in an annular groove formed in the periphery of the grain breaking roller, and the grain breaking edge of the roller constitutes the outer terminus of the floor of said groove said groove floor being spaced below the abutment terminus of the curved flanging surface of the die the distance of a predetermined normal lap seam thickness.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims, and the several views illustrated in the accompanying drawings.

In the drawings:

Figure 1 is a side elevation illustratin the improved can body flanging apparatus.

Figure 2 is an enlarged fragmentary sectional view illustrating the cooperation of the flanging die and the grain breaking roller in flanging a can body, the commencement of the cooperation being shown.

Figures 3 and 4 are views similar to Figure 2 and illustrate successive stages in the formation of the can body flange, the completion of the flange turning function being illustrated in Figure 4.

Figure 5 is a view similar to Figure 4 illustrating engagement of the grain breaking roller with the side seam of a can.

Figure 6 is an enlarged fragmentary sectional view illustrating somewhat diagrammatically how the grain breaking roller edge breaks the grain of the flange and reduces the resistance to bending thereof over a predetermined area and in a manner for definitely determining the length of the body hook to be turned in the seam sealing of the container. 7

Figure 7 is a somewhat diagrammatic enlarged sectional View illustrating the flange of Figure 6 turned into a hook.

Figure 8 is a view similar to Figure 6, the section being taken at the position of the can body side seam.

Figure 9 is a view similar to Figure '7 i11ustrating the lapped flange portion of Figure 8 turned into a hook as it would appear in the can after the closure is seam secured thereon, the closure being shown in dotted line phantom.

In the apparatus herein disclosed, and which constitutes an example of embodiment of the invention adaptable for practicing the method forming a part of the invention, there is included a can body support or base plate 5 having a can body centering plug extension 6 thereon for entering an end of a can body I which is to be flanged. The base plate 5 is rotatably mounted on the upper end of a plunger 8 which is vertically reciprocable in a bearing 9 to which a lever I6 is pivoted intermediately of its end as at II, the short end of the lever being pin-connected as at I2 to the plunger 8. It will be obvious by reference to Figure 1 that by lifting or lowering the long end of the lever I0, the base plate 5 can be lowered or lifted.

A flanging die generally designated I3 is mounted above and in cooperative relation to the base plate 5, said die being mounted on the lower end of a shaft I4 which is rotatable in bearings I5 formed in a frame housing I6. Within the housing, the shaft I4 is bevel-coupled as at I I with a driver shaft I 8 rotatably mounted in bearings I9 provided in the frame housing I6 and in the frame extension 20 whereon is mounted an electric motor 2| which is gear coupled as at 22 with the drivin shaft I8. It will be obvious that when the motor 2| operates it will impart rotation to the shaft I8 through the gear couple 22, and to the shaft I4 and flanging die I3 through the gear couple I 'I. Whenever a can body I is placed upon the base plate 5 and the lever I0 is depressed so as to lift the can body and tightly engage the same with the flanging die I3, said can body will be caused to be rotated with the flanging die.

The flanging die generally designated I3 is provided with anoutwardly directed flange 23, and a can body centering plug or extension 24 depends below the flange 23 in position for entering the upper end of the can body which is to be flanged in the manner clearly illustrated in Figures 1 to 4. The die I3 also is equipped'with an upwardly and outwardly urved hang g-surface 2.5 term atin outw rd y in a u dercutzfi in the low r face o the. fla g 2 the termin s of: sa dund utqser ing to provide an abutment shoulder 2;! whichis effective to definitely determine the extent of outward turning of the can body flange. It will be apparent by reference to Figures 2, 3, 4, and 5 of the drawing that the depth of the undercut, or in other words the depth of the abutment shoulder 21', is substantially the proper thickness of the lap portion of a side seam, or in other words the double lap thickness of the stock from which the can body is formed plus the thickness of a proper solder bond As an outstanding feature oi the invention, there is provided a grain breaking roller-2 8 having an annular groove 29 in the periphery dimensioned to snugly receive the outwardly directed flange 23 of the flanging die l3 so as to constantly maintain the proper cooperative relation of the. flanging die and grain breaking roller illustrated in Figures 1 to l. The floor of the groove 29 terminates outwardly in a grain breaking edge 30 which is adapted to be held against the can body flange as it is being turned in the manner clearly illustrated in Figures 2, 3. 4 and 5.

The grain breaking roller 28 is mounted on a shaft 3! in a bifurcated head 32 which is rockably mounted on ofi center trunnion bearings 33 in a frame extension 34. The bifurcated head .32 is equipped with an actuator handle 35 whi h may be manipulated to control the position of the grain breaking roller 28 formoving the same into operative position and holding the same in said operative position against the can body flange as it is being formed in the manner illustrated in Figures 3, 4 and 5, or for moving said roller out of contact.

In practicing the invention, a can body I is placed upon the base plate 5 in the manner indicated in dot and dash lines in Figure 1, and the handle i0 is depressed to elevate the can body into contact with the flanging surface 25 of the flanging die It and for holding the same tightly thereagainst. the flanging die l3 will be imparted to the can body 1 and the base plate 5, it being understood that the base plate is free to rotate relative to the supporting plunger 8. By depressing the lever l0 and forcing the can body 1 upwardly, the upper end of the can body will be caused to move endwise over the upwardly and outwardly curved flanging surface 25 in the manner clearly illustrated in Figures 2 and 3, and while this flange turning is progressing, the grain breaking edge 36 of the roller is held tightly against the flange as it is being turned, thereby breaking the grain at the outside of the turning flange and tightly pressing said flange against the flangin surface 25 and causing said flange to conform in curvature to said surface. Contact of the edge extremi-ty of the outwardly turned can body flange with the abutment shoulder 21'! will serve to definitely determine the extent of outward turning of the said flange in the manner clearly illus" vtrated in Figure 4.

Figure 6 is an enlarged fragmentary sectional view clearly illustrating the manner in which the the grain breaking edge 30 of the roller 28 breaks the grain the outwardly turned flange so as to reduce the resistance to bending of the flange over the portions thereof contacted by the roll edge and definitely determine the length the bodyhook will have when subsequently formed in the seam securi g of a c osure the As before stated, the rotation of body. .In this figure, the breaking or the grain by progressive contact or the roller edge 38 therewith in the manner illustrated in Figures 2 3 and e is illustrated by the wavy lines 36. By terminating the grain breaking contact of the roller edge 30 at the point or line indicated i f 'Figure 6, said point or line bearing definite spaced relation to the circumferential retaining wall or abutment shoulder 21, the grain breaking is accomplished over a predetermined definite circumferential area of the outwardly turned flange so as to definitelydetermine the length of the body hook of the form illustrated in Figure '7. Figure 7 is a somewhat diagrammatic sectional view illustrating the flange of Figure 6 turned into a body hook. the wavy lines 36 indicating the mannerin which the broken grain determines the place at which the hook is bent and consequently the length of the hook. It is well known that in the turning of the body hook incidental to the seam securing of a closure on the can body, a portion of the flange turned in the manner illustrated in Figure 6 is displaced inwardly back in line with the main body wall portion, as will be apparent by a comparison of Figures 6 and 7.

It will be apparent that when the grain breaking roller edge 38 is held against the can body flange in the manner above described, theroller Z8 revolves by frictional contact with the can body stock, and simultaneously with the breaking of the grain as aforesaid, the body stock being turned into the flange is caused to conform to the curvature of the hanging surface 25 while the outwardly turning extremity of the flange is bein directed toward and against the abutment shoulder 2 i.

While the shaping of the flange and the breaking of the grain therein provides very beneficial results in the turning of the single thickness portion of the flange, the advantageous features of the invention are to be appreciated .to an. even greater extent at the cross-over area or the position of the lap portion of the look and lap seams usually provided in can bodies, for it is at this point that the greatest problem with respect to rupturing of the solder bond in the lapped seam portion and the formation of uniform hooks is experienced. In Figures 5, 8 and 9 of the drawings, the advantages of the invention are illustrated connection with the practicing of the method and the functioning of the apparatus at the cross-over area or lap seam portion. Figure 8 is View similar to Figure 6 illustrating the engagement of the grain breaking edge 36 of the roller 28 at the lap seam portion. In this i1lustration the wavy lines indicate the portion of thelap flange in which the grain has been broken so as to reduce the resistance to bending and definitely determine the point or line at which the lapped flange pertion will turn downwardly in h fo matio of the od ho k h na closure has been seam secured en the body in the mannerindicated in dotted line phantom in Fig .ure 9. Figure .8 clearly illustrates how the provision of the definite spacin bet-ween the die flfinging wall 26 and the floor of the roller groove 25 Which terminates at the grain breaking edge 3d serves to determine the desired definite thickness of the lapped portion of the side-seam. As has beenstated hereinabove, the depth of the -un dercut producing the abutment shoulder 23' is substantially that of two thicknesses of the can body stock, or in other words the thickness of the usual lap provided at the of the lock audlap seam, in ud ng, 9! course. the add r bond. In can bodies which might carry an excess of seam bonding solder S, the malleable solder would be caused to flow and become somewhat thinned in the manner clearly illustrated ST in Figure 8.

It will be apparent by reference to Figure 8 than in the flanged can body the thickness of the solder in the unflanged part of the lap seam portion is greater than in the flanged portion thereof, and the illustration in Figure 8 will serve to show how by practicing the herein described method of seam lap portion which has an unnecessarily thick solder bond will be suitably reduced in thickness. When the lapped thickness portion of a side seam passes between the grain breaking edge 30 and the fianging surface 25 as the flange is first being formed, the roll edge sizes this thickness, if thicker than standard, by first causing the solder to be thinned in the region of roll edge contact. If the tin plate also is thicker than normal, the roll edge acts on the tin plate at the same time, tending to flow the metal to a thinner gauge. As the edge of the can flange passes beyond the roll edge 38, Figure 8, there is a fixed space X--Y in which the flange metal (tin plate and solder) can be housed. If the lap seam portion thickness is greater than the depth of this space, the rolling action and squeezing of the groove floor as the lap passes through, will size said thickness to the desired dimension.

It has been found that the spreading of excess bonding solder has no effect in diminishing the efliciency of the bond, and in this manner the desired uniformity of flange thickness is assured. Obviously this feature augments the feature of determining the diameter or outward extension of the flange by provision of the circumferential abutment wall 21, and the feature of breaking the grain of the flange over a definite predetermined circumferential area, in the provision of body hooks of predetermined definite length.

It should be understood that as the grain breaking edge 30 of the roller 28 is forced against the single flange thickness as illustrated in Figure 6 and the double flange thickness at the lap seam as illustrated in Figure 8, said edge tends to embed itself slightly in the body metal and turn the same as the grain breaking function is being performed.

It will be apparent from the foregoing that by practicing the herein disclosed method, the turning of the body hook both at the single thickness and the double thickness or lap seam portion is greatly facilitated during the seam securing of an end closure on the can body, in addition to the provision of the formation of body hooks of uniform length. The action of the grain breaking roll breaks the grain of the metal and the solder, taking the stiffness out of each so that the action of the cover pressure and the seaming roll will result in the provision of uniform seams and cans of uniform length.

Another advantage is that of providing uniform thicknesses of the lap seam portions at the flange.

these features making it possible to limit the diameter of the body flang to a predetermined standard effective to provide just the right length of body hook as aforesaid.

While one form of apparatus is herein disclosed as a practical example of the invention and a means for practicing the method forming a part of the invention, it is to be understood that various changes in the details of construction and arrangement of parts may be made without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. The herein described method of fianging can bodies which comprises, gradually and progressively bringing about endwise contact between the can body and a rotating outwardly curved flanging surface formed on a fianging die extending within the body while simultaneously pressing a grain breaking roll externally against the metal that is to constitute the finished flange, thereby breaking the grain of the metal as it passes between the grain breaking roll and said curved fianging surface and shaping it to and against said outwardly curved fianging surface to the predetermined limit of a circumferential retaining wall of greater diameter than the can body.

2. The herein described method of fianging can bodies which comprises, gradually and progressively bringing about endwise contact between the can body and a rotating outwardly curved flanging surface formed on a fianging die extending within the body while simultaneously pressing a grain breaking roll externally against the metal that is to constitute the finished flange, thereby breaking the grain of the metal as it passes between the grain breaking roll and said curved fianging surface, and terminating the grain breaking roll contact at a line about the turned flange at which the flange is subsequently to be turned to form the body hook, thereby to reduce the resistance to bending of the flange over the portions thereof contacted by the roll and definitely determining the length the hook will have when subsequently formed.

3. The herein described method of fianging can bodies which comprises, holding a can body against a fianging die having an outwardly curved fianging surface extending into the can body, rotating the contacting die and can body, forcing the die and can body together to cause the end edge portion to move endwise over the outwardly curved fianging surface so as to turn said edge portion outwardly, and pressing a rotating grain breaking edge against the longitudinally moving outwardly turning and rotating flange so as to press it against the curved fianging surface as the flange is being turned and cause said flange to conform to said curved fianging surface.

. 4. The herein described method of fianging can bodies which comprises, holding a can body against a fianging die having an outwardly curved fianging surface extending into the can body. rotating the contacting die and can body, forc ing the die and can body together to cause the end edge portion to move endwise over the outwardly curved fianging surface so as to turn said edge portion outwardly, and pressing a ro tating grain breaking edge against the longitudinally moving outwardly turning and rotating flange so as to press it against the curved flanging surface as the flange is being turned and cause said flange to conform to said curved fianging surface and also break the grain and reduce the grasses 9 a, rese -e is an rad smen d fies circumferential portion of said flange inwardly of the edge 'eirt rejrnity thereof thereby to definitely predete'rm'ine the amount of flange that will subsequently "be bent into a body hookincidental to the seam securing of a closure n the canbody, N g g 5, The 'e ein described methodlof flangin'g can bodies which comprises, forcing the can body end pbftibn ifia s ,afi ise l ai ta ot ti outwardly cur'veasurraee extending into the can body thereby to turn said end edge portion into an outwardly directed flange, and while turning said flange tightly pressing a grain breaking roller edge against the outwardlyturning and rotating flangein opposition to said curved surface to cause the outwardly turning flange to conform incurva ture to the curvature of said curved surface and to reduce the resistanceto bending of a definite circumferential area of the flange as to p'redeterinine "the length or bedy hook it will 'siflosequently be formed during the seanrs curing or 'aciosurefon said canbody.

'6. The herein described method of flan'g'i'n'gcan bodies having side seams including solder bonded lapped thickness portions which comprises, gradually and progressively bringing about endwise contact between the can body and a rotating outwardly curved flanging surface extending within the body While simultaneously pressing a grain breaking roll externally against the metal that is to constitute the flange and including the lapped thickness portion and its solder bond, thereby breaking the grain of the metal as it passes between the grain breaking roll and the flanging surface and shaping it to the outwardly curved flanging surface to the predetermined limit of a circumferential retaining wall and also thinning the lapped and solder bonded flange thickness to a predetermined standard.

7. The herein described method of flanging can bodies having side seams including solder bonded lapped thickness portion which comprises, gradually and progressively bringing about endwise contact between the can body and a rotating outwardly curved flanging surface extending within the body while simultaneously pressing a grain breaking roll externally against the metal that is to constitute the flange and including the lapped thickness portion and its solder bond, thereby breaking the grain of the metal as it passes between the grain breaking roll and the flanging surface and shaping it to the outwardly curved flanging surface to the predetermined limit of a circumferential retaining wall and also thinning the lapped and solder bonded flange thickness to a predetermined standard, and terminating the grain breaking roll contact at a line about the turned flange at which the flange is subsequently to be turned to form the body hook, thereby to reduce the resistance to bending of the flange over the portions thereof contacted by the roll and definitely determining the length the hook will have when subsequently formed, both in the single body thickness and the lapped thickneSs solder bonded seam portion,

8. The herein described method of flanging can bodies having side seams including solder bonded lapped thickness portions which comprises, forcing the can body end portion to be flanged endwise against a rotating outwardly curved surface extending into the can body thereby to turn said edge portion into an outwardly directed flange, and while turning said flange tightly pressing a grain breaking roller edge against the outwardly turningand otating flange "in opposition to said curved surface to causethe flange includingthe lapped thickness portion and its solder bond to conform to the curvature of said curved surface and have its resistance to bending reduced over a definite circumferential area so as to prdeter mine theler' gth'dr ody hook whichwill subse duently be fdrmed during the seam se'curingof afclos'ureon the canbddy; both in the single body if kness and the lapped thickness "solder bonded p tion, and directing said 'as it is being 1 led and turned 'i ntofa receivirigspace of predetermined thickness effectivetoreduce ai'e i a lapped l h s aa fso r ba de se'ain por tq the predetermined standard detei'niin bys id'space. V v

=9; in sea bodyfflan'ging apparatus, a flanging as having a portion re'ceivable in the end ofa can body to be 'flariged and includingfan outwardly curved flanging surface, means for suppdrting a can bddy m cansidr bringing "about relative endwise mo" mentb'etween the die and 1? fi ri s fe t h as tear n d n rtion endwise over the curved'fla nging surface, a grain breaking edge engageable against the external surface of the can body end edge portion as it is being forced endwise over the curved flanging surface, and means for bringing about relative rotation between the grain breaking edge and the die and can body being flanged thereagainst.

10. Apparatus as defined in claim 9 in which the grain breaking edge is provided on a roll engageable in rolling contact with the can body end edge portion being flanged.

11. Apparatus as defined in claim 9 in which the flanging die includes an outwardly directed flange and the outwardly curved flanging surface merges into a wall constituting an undercut in the under surface of said die flange, said undercut being defined outwardly by an upright abutment shoulder disposed to definitely limit the extent of outward turning of the can body flange.

12. Apparatus as defined in claim 9 in which the grain breaking edge is provided on a roll engageable in rolling contact with the can body end edge portion being flanged, and in which the flanging die includes an outwardly directed flange, said roll having an annular groove in its periphery dimensioned to snugly but movably receive the flanging die flange and prevent relative movement of said die and roll in the direction of their axes thereby to maintain the grain breakin edge and the outwardly curved flanging surface in proper cooperative relation.

13. Apparatus as defined in claim 9 in which the grain breaking edge is provided on a roll engageable in rolling contact with the can body end edge portion being flanged, and in which the flanging die includes an outwardly directed flange, said roll having an annular groove in its periphery dimensioned to snugly but movably receive the flanging die flange and prevent relative movement of said die and roll in the direction of their axes thereby to maintain the grain breaking edge and the outwardly curved flanging surface in proper cooperative relation, said flanging die outwardly curved surface merging into a wall constituting an undercut in the under surface of said flanging die flange, said undercut being defined outwardly by an upright abutment shoulder disposed to definitely limit the extent of outward turning of the can body flange.

14. Apparatus as defined in claim 9 in which the grain breaking edge is provided on a roll engageable in rolling contact with the can body end edge portion being flanged, and in which the flanging die includes an outwardly directed flange, said roll having an annular groove in its periphery dimensioned to snugly but movably receive the fianging die flange and prevent relative movement of said die and roll in the direction of their axes thereby to maintain the grain breaking edge and the outwardly curved flanging surface in proper cooperative relation, said flanging' die outwardly curved surface merging into a wall constituting an undercut in the under surface of said flanging die flange, said undercut being defined outwardly by an upright abutment shoulder disposed to definitely limit the extent of outward turning of the can body flange, said grain breaking edge being disposed at the outer terminus of the roll undercut wall, and said groove floor being spaced above the roll groove floor the distance of a predetermined normal lap seam thickness.

15. Apparatus as defined in claim 9 in which the grain breaking edge is provided on a roll engageable in rolling contact with the can body end edge portion being flanged, and in which the JOHN COYLE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,413,594 White Dec. 31, 1946 348,396 James Aug. 31, 1886 408,774 Walsh Aug. 13, 1889 540,613 Gates June 4, 1895 

